If the exhaustion you feel at the end of the work day wasn’t evidence enough, the career experts at PayScale have analyzed the data and delivered the proof: Workers in the oil industry have the most grueling work weeks.

In an analysis of jobs in which most workers receive hourly wages, energy-related professions claimed six of the top 10 longest work weeks. Roustabouts take the top spot, with a median work week of 61 hours. Drillers are not far behind, with a median of 59 hours per week, according to PayScale.

But the oil industry compensates well for the long hours. Workers in the energy industry also were among the highest paid, with petroleum plant operators earning the highest median wage in the top 10 — $25.48.

PayScale is an online service that surveys workers with various job titles on wages, salaries and other career data.